Epidemiology of post-pancreatitis diabetes mellitus

Abstract

Background: Post-pancreatitis diabetes mellitus (PPDM) is the most common subtype of diabetes of the exocrine pancreas, but there is a paucity of population-based studies on PPDM. The only population-based study demonstrated that PPDM led to poorer glycaemic control compared with type 2 diabetes. The aim of this doctoral research was to comprehensively investigate epidemiological characteristics (mortality outcomes, morbidity outcomes, and risk factors) of PPDM. Methods: Nationwide healthcare utilisation data (hospital discharge data, pharmaceutical dispensing data, cancer registry data, and mortality data) of individuals who were admitted for pancreatitis, pancreatic cancer, and diabetes mellitus were obtained from the Ministry of Health Analytical Services (National Health Board, New Zealand). The data included information on demographics, date of diagnosis, diagnostic codes, date of pharmaceutical dispensing, chemical name, death date, and cause of death. A series of multivariable Cox regression analyses were conducted. Results: In individuals with PPDM, the mean age was approximately 64 years and the proportion of women was 41%. Compared with type 2 diabetes, PPDM yielded 14.8 excess deaths per 1,000 person-years. Compared with type 1 diabetes, PPDM was associated with a 65% significantly higher risk of cancer mortality, with young women with PPDM being a high-risk group for cancer mortality. In individuals with PPDM, metformin use was associated with a 49% significantly lower risk of all-cause mortality compared with never use of anti-diabetic medications. Insulin use was associated with a 3.9-times significantly increased risk of progression of pancreatitis in individuals with PPDM. Individuals with PPDM were at a 6.9-times significantly higher risk of pancreatic cancer compared with those with type 2 diabetes. Among individuals with pancreatitis, PPDM was associated with a 4.4- times significantly increased risk for mental disorders. Exocrine pancreatic dysfunction (3.8- times), ≥2 recurrent biliary events (at least 2.0-times), and gout (1.6-times) were significantly associated with increased risks of PPDM, as compared with absence of each of the risk factors. Conclusions: The findings suggest that PPDM is associated with worse mortality and morbidity outcomes compared with other types of diabetes. The risk factors for PPDM identified in this research were exocrine pancreatic dysfunction, recurrent biliary events, and gout.